Interlock device of ring main unit

ABSTRACT

The present invention relates to an interlock device of a ring main unit, and more particularly, to an interlock device of a ring main unit in which a fuse cover can be closed in interlock with a cable cover. 
     An interlock device of a ring main unit according to an embodiment of the present disclosure may include an interlock frame provided in part of the ring main unit, a cam on part of which an engaging portion is protruded and formed and on the other part of which a slit is formed, rotatably provided within the interlock frame, an operating plate an end of which is coupled to the slit to perform a vertical movement, and a spring an end of which is fixed to part of the cam to store an elastic force due to the movement of the cam.

CROSS-REFERENCE TO RELATED APPLICATIONS

Pursuant to 35 U.S.C. §119(a), this application claims the benefit ofearlier filing date and right of priority to Korean Patent ApplicationNo. 10-2015-0010786, filed on Jan. 22, 2015, the contents of which arehereby incorporated by reference herein in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the invention

The present invention relates to an interlock device of a ring mainunit, and more particularly, to an interlock device of a ring main unitin which a fuse cover can be closed in interlock with a cable cover.

2. Description of the related art

In general, as a device used to monitor, control and protect anelectrical system configured to transmit and distribute power sent tocustomers through transmission and distribution, ring main unit (RMU)may be configured with an assembly of a circuit breaker, a switchgear,grounds and conductors within a structure that is sealed and insulatedby SF6 gas.

A ring main unit according to the related art is illustrated in FIG. 1,and a configuration in which a fuse cover and a cable cover are removedfrom the configuration of FIG. 1 is illustrated in FIG. 2. A fuse cover2 and a cable cover 3 are provided on a front surface of a ring mainunit 1, and various apparatus such as a circuit breaker, a switch, adisconnecting switch, an earth switch and the like are housed within thering main unit 1 and interlock devices are provided therein to controltheir operations.

Among those interlock devices, an interlock device implemented in thefuse cover 2 has two types of functions. The first function is afunction to allow the opening of the fuse cover 2 only when in a groundstate in connection with an operating mechanism of the relevant circuit.The second function is a function to allow the opening of the cablecover 3 only in a state that the fuse cover 2 is open when both thecable cover 3 and fuse cover 2 are mounted thereon. Through this, thefuse cover 2 may be allowed to be open only when an operating mechanismof the relevant circuit is in a ground state, and the cable cover 3 maybe also allowed to be open only in a state that the fuse cover 2 isopen.

Furthermore, an interlock device for interlocking the operatingmechanism of the relevant circuit with the fuse cover 2 may be alsoapplied not to operate the relevant operating mechanism in a state thatthe fuse cover 2 is open.

However, when both the fuse cover 2 and cable cover 3 are open and thenthe fuse cover 2 is closed while the operating mechanism of the relevantcircuit is in a ground state, the operating mechanism of the relevantcircuit will be in an always operable state. In this case, the relevantcircuit will be in an always-on state, and thus there is a risk ofaccident such as dielectric breakdown due to contact when a personapproaches a cable portion through which electricity flows in an activestate.

SUMMARY OF THE INVENTION

The present invention is contrived to solve the foregoing problems, andan aspect of the present invention is to provide an interlock device ofa ring main unit configured to interlock a cable cover with a fuse coverso as to close the fuse cover only when the cable cover is in a closedstate.

An interlock device of a ring main unit according to an embodiment ofthe present disclosure may include an interlock frame provided in partof the ring main unit, a cam on part of which an engaging portion isprotruded and formed and on the other part of which a slit is formed,rotatably provided within the interlock frame, an operating plate an endof which is coupled to the slit to perform a vertical movement, and aspring an end of which is fixed to part of the cam to store an elasticforce due to the movement of the cam.

Here, a fuse cover of the ring main unit may not be closed when theengaging portion is placed in a state of being protruded to an outsideof the interlock frame.

Furthermore, a through hole into which the operating plate can beinserted may be formed on a lower surface of the interlock frame.

Furthermore, a shaft hole into which a rotating shaft configured torotatably support the cam within the interlock frame can be inserted maybe formed on part of the cam.

Furthermore, the interlock device may further include a bush providedbetween one sidewall of the interlock frame and the cam to rotatablysupport the cam.

Furthermore, the operating plate may include a front plate and a rearplate, and an engaging plate with which a cable cover can be broughtinto contact may be protruded and formed in a forward direction on thefront plate.

Furthermore, a coupling hole provided with a coupling shaft that can beinserted into the slit may be formed on the rear plate. Furthermore, aroller may be provided on the coupling shaft to smoothly move within theslit.

Furthermore, a guide plate configured to assist a vertical movement ofthe operating plate may be provided in part of the interlock frame.

Furthermore, an end of the spring may be fixed and provided on a springhole formed on part of the cam, and the other end of the spring may befixed and provided in part of the interlock frame.

In addition, the operating plate may be placed at a lowered positionwhen the cable cover is closed.

According to an interlock device of a ring main unit in accordance withan embodiment of the present disclosure, a fuse cover may be closed onlywhen a cable cover is closed and thus a main circuit may not be allowedto be on in a state that the cable cover is open, thereby obtaining aneffect of preventing safety accidents.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate embodiments of the invention andtogether with the description serve to explain the principles of theinvention.

In the drawings:

FIG. 1 is a front view illustrating a ring main unit according to therelated art;

FIG. 2 is a view illustrating a state in which the fuse cover and cablecover are removed from the configuration of FIG. 1;

FIG. 3 is a perspective view illustrating an interlock device state whenthe fuse cover and cable cover are mounted in a ring main unit accordingto an embodiment of the present disclosure;

FIG. 4 is a perspective view illustrating an interlock device state whenonly the fuse cover is mounted and the cable cover is removed in a ringmain unit according to an embodiment of the present disclosure;

FIG. 5 is a perspective view of an interlock device in a ring main unitaccording to an embodiment of the present disclosure;

FIG. 6 is an exploded perspective view illustrating constituent elementsexcluding an interlock frame in FIG. 5;

FIG. 7 is a bottom perspective view of FIG. 5;

FIG. 8 is a perspective view illustrating a fuse cover applied to anembodiment of the present disclosure;

FIG. 9 is a perspective view illustrating a cable cover applied to anembodiment of the present disclosure;

FIG. 10 is an operational state diagram of an interlock device accordingto the present disclosure illustrating a state in which the cable coveris separated; and

FIG. 11 is an operational state diagram of an interlock device accordingto the present disclosure illustrating a state in which the cable coveris mounted.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, a preferred embodiment of the present invention will bedescribed in detail with reference to the accompanying drawings to suchan extent that the present invention can be easily implemented by aperson having ordinary skill in the art to which the present inventionpertains, but it does not mean that the technical concept and scope ofthe present invention are limited due to this.

FIG. 3 is a perspective view illustrating an interlock device state whenthe fuse cover and cable cover are mounted in a ring main unit accordingto an embodiment of the present disclosure, and FIG. 4 is a perspectiveview illustrating an interlock device state when only the fuse cover ismounted and the cable cover is removed, and FIG. 5 is a perspective viewof an interlock device in a ring main unit according to an embodiment ofthe present disclosure, and FIG. 6 is an exploded perspective viewillustrating constituent elements excluding an interlock frame in FIG.5, and FIG. 8 is a perspective view illustrating a fuse cover applied toan embodiment of the present disclosure, and FIG. 9 is a perspectiveview illustrating a cable cover applied to an embodiment of the presentdisclosure. An interlock device of a ring main unit according to eachembodiment of the present disclosure will be described in detail withreference to the drawings.

Referring to FIGS. 3 through 7, an interlock device of a ring main unitaccording to an embodiment of the present disclosure may include aninterlock frame 20 provided in part of the ring main unit 10; a cam 30on part of which an engaging portion 32 is protruded and formed and onthe other part of which a slit 31 is formed, rotatably provided withinthe interlock frame 20; an operating plate 40 an end of which is coupledto the slit 31 to perform a vertical movement; and a spring 50 an end ofwhich is fixed to part of the cam 30 to store an elastic force due tothe movement of the cam 30.

The interlock frame 20 may be formed with a plate. The interlock frame20 may be formed in a box shape in which an upper surface thereof isopen. A member for installation 21 may be provided in part of theinterlock frame 20, and a coupling hole 22 may be formed on the memberfor installation 21 and installed in part of the ring main unit 10.Here, the interlock frame 20 may be installed on a rear portion of thefuse cover 11 and cable cover 12. A through hole 23 into which theoperating plate 40 which will be described later can be inserted may beformed on a lower surface of the interlock frame 20.

The cam 30 may be formed with a substantially triangular plate (ofcourse, the cam 30 may be formed in various shapes according to theembodiments). The engaging portion 32 protruded upward may be formed ata first edge of the cam 30. Furthermore, a spring hole 33 for couplingthe spring 50 thereto may be formed at the first edge of the cam 30. Aslit 31 consisting of an elongated hole is formed at a second edge ofthe cam 30. A shaft hole 34 into which the rotating shaft 36 can beinserted to be rotatably coupled to the interlock frame 20 is formed ata third edge of the cam 30. The rotating shaft 36 rotatably supports thecam 30 within the interlock frame 20.

The rotating shaft 36 is coupled to one sidewall of the interlock frame20 through the shaft hole 34. The rotating shaft 36 may be configuredwith a shaft bolt. A bush 38 may be provided to maintain a distancebetween the cam 30 and the interlock frame 20. The bush 38 is providedbetween the cam 30 and one sidewall of the interlock frame 20 torotatably support the cam 30. A rotating ring 37 may be provided betweenthe rotating shaft 36 and the cam 30 to reduce a rotational friction.

The operating plate 40 may be formed in a “U”-shape to have a frontplate 41 and a rear plate 42. A plurality of engaging plates 43protruded in a forward direction may be formed on the front plate 4. Theengaging plate 43 is a portion with which an upper surface 12 a of thecable cover 12 which will be described later is brought into contact.

A coupling hole 44 is formed on part of the rear plate 42 of theoperating plate 40 to install a coupling shaft 45 passing through theslit 31. The coupling shaft 45 may be configured with a shaft bolt. Anut 46 and a washer 47 may be provided to fix the coupling shaft 45.

The operating plate 40 is coupled to the slit 31 of the cam 30 in asliding manner by means of the coupling shaft 45. Here, a roller 35 maybe provided to smoothly move the coupling shaft 45 on the slit 31. Theroller 35 is provided between the coupling shaft 45 and the slit 31 tosmoothly perform the movement of the operating plate 40.

A guide plate 60 is provided to assist a vertical movement of theoperating plate 40. The guide plate 60 is provided in part of theinterlock frame 20 to support the rear plate 42 of the operating plate40. The operating plate 40 may perform a vertical movement by means ofthe guide plate 60.

The rear plate 42 of the operating plate 40 is inserted and providedinto a through hole 23 of the interlock frame 20. In other words, theoperating plate 40 performs a vertical movement through the through hole23. As a result, the operating plate 40 performs only a verticalmovement without being rotated or swayed by means of the through hole23.

A spring 50 is provided to transfer the cam 30 to a position on whichthe engaging portion 32 faces upward. An end of the spring 50 is fixedand provided on a spring hole 33 formed at a first edge of the cam 30,and the other end of the spring 50 is fixed and provided in part of theinterlock frame 20. Bolts 55, 56, nuts 57, 58 and a washer 59 may beprovided to fix the spring 50. The spring 50 may be configured with anelastic coil spring.

The operation of an interlock device in a ring main unit according to anembodiment of the present disclosure will be described with reference toFIGS. 3, 4 and 8 through 11.

When an external force is not applied thereto, the cam 30 receives aforce of the spring 50 and is located at a position on which theengaging portion 32 faces upward. The engaging portion 32 of the cam 30is protruded upward, and therefore, the fuse cover 11 is placed in anon-closed state. Specifically, the engaging portion 32 of the cam 30 isengaged with a protruded surface 11 a of the fuse cover 11, and thusfuse cover 11 is unable to be closed.

The cable cover 12 is closed in a manner of being pushed downward fromthe top. When the cable cover 12 is closed, the upper surface 12 a ofthe cable cover 12 pushes the engaging plate 43 in a downward directionto move the operating plate 40 downward. As the operating plate 40 movesdownward, the coupling shaft 45 provided at a second edge of the cam 30rotates the cam 30 in a clockwise direction while moving downward suchthat the engaging portion 32 is hidden inside the interlock frame 20.Here, the vertical movement of the operating plate 40 is smoothlyconverted into a rotational movement of the cam 30 by means of theroller 35 operating within the slit 31 as described above. As theengaging portion 32 is hidden inside the interlock frame 20, the fusecover 11 is closed.

According to an interlock device of a ring main unit in accordance withan embodiment of the present disclosure, the fuse cover may be closedonly when the cable cover in interlock with the fuse cover is closed.

As a result, opening both the fuse cover and cable cover in a state thatthe operating mechanism of the relevant circuit is grounded and thenclosing only the fuse cover in a state that the cable cover is notclosed may be prevented, thereby obtaining an effect of preventingsafety accidents.

The foregoing embodiments are embodiments for implementing the presentdisclosure, and it will be apparent to those skilled in this art thatvarious changes and modifications may be made thereto without departingfrom the gist of the present invention. Accordingly, it should be notedthat the embodiments disclosed in the present invention are onlyillustrative and not limitative to the concept of the present invention,and the scope of the concept of the invention is not limited by thoseembodiments. The scope protected by the present invention should beconstrued by the accompanying claims, and all the concept within theequivalent scope of the invention should be construed to be included inthe scope of the right of the present invention.

What is claimed is:
 1. An interlock device of a ring main unit, theinterlock device comprising: an interlock frame provided in part of thering main unit; a cam on part of which an engaging portion is protrudedand formed and on the other part of which a slit is formed, rotatablyprovided within the interlock frame; an operating plate an end of whichis coupled to the slit to perform a vertical movement; and a spring anend of which is fixed to part of the cam to store an elastic force dueto the movement of the cam, wherein a fuse cover of the ring main unitis not closed when the engaging portion is placed in a state of beingprotruded to an outside of the interlock frame.
 2. The interlock deviceof claim 1, wherein a through hole into which the operating plate can beinserted is formed on a lower surface of the interlock frame.
 3. Theinterlock device of claim 1, further comprising: a rotating shaftconfigured to rotatably support the cam within the interlock frame,wherein a shaft hole into which the rotating shaft can be inserted isformed on part of the cam.
 4. The interlock device of claim 3, furthercomprising: a bush provided between one sidewall of the interlock frameand the cam to rotatably support the cam.
 5. The interlock device ofclaim 1, wherein the operating plate comprises a front plate and a rearplate, and an engaging plate with which a cable cover can be broughtinto contact is protruded and formed in a forward direction on the frontplate.
 6. The interlock device of claim 5, wherein a coupling holeprovided with a coupling shaft that can be inserted into the slit isformed on the rear plate.
 7. The interlock device of claim 6, wherein aroller is provided on the coupling shaft to smoothly move within theslit.
 8. The interlock device of claim 1, wherein a guide plateconfigured to assist a vertical movement of the operating plate isprovided in part of the interlock frame.
 9. The interlock device ofclaim 1, wherein an end of the spring is fixed and provided on a springhole formed on part of the cam, and the other end of the spring is fixedand provided in part of the interlock frame.